正则表达式匹配单点而不匹配两个点? [英] Regular expression to match single dot but not two dots?
问题描述
尝试创建用于电子邮件地址检查的正则表达式模式.这将允许一个点(.)，但如果相邻的点不止一个.
Trying to create a regex pattern for email address check. That will allow a dot (.) but not if there are more than one next to each other.
应匹配: test.test@test.com
Should match: test.test@test.com
不应匹配: test..test @ test.com
Should not match: test..test@test.com
现在，我知道互联网上有成千上万个用于电子邮件匹配的示例，所以请不要向我发布包含完整解决方案的链接，我正在尝试在这里学习.
Now I know there are thousands of examples on internet for e-mail matching, so please don't post me links with complete solutions, I'm trying to learn here.
实际上，最让我感兴趣的部分只是本地部分: 应该匹配的test.test和应该不匹配的test..test. 感谢您的帮助.
Actually the part that interests me the most is just the local part: test.test that should match and test..test that should not match. Thanks for helping out.
推荐答案
您可以使用在它们之间进行分离(管道符号|)，并将带有*(其中任意数量)的整个内容放在^和$之间，以便整个字符串由这些组成.这是代码:
You may allow any number of [^\.] (any character except a dot) and [^\.])\.[^\.] (a dot enclosed by two non-dots) by using a disjunction (the pipe symbol |) between them and putting the whole thing with * (any number of those) between ^ and $ so that the entire string consists of those. Here's the code:
$s1 = "test.test@test.com";
$s2 = "test..test@test.com";
$pattern = '/^([^\.]|([^\.])\.[^\.])*$/';
echo "$s1: ", preg_match($pattern, $s1),"<p>","$s2: ", preg_match($pattern, $s2);
收益:
test.test@test.com: 1
test..test@test.com: 0
这篇关于正则表达式匹配单点而不匹配两个点?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
